The invention relates to a filter closure system for seal-tightly connecting the connecting end at the end face of a filter housing to a connecting head that matches the connecting end and onto which the connecting end can be pushed in a mounting direction. Such a filter closure system serves for producing a pressure-tight and/or gas-tight and/or liquid-tight sealed connection between the filter housing and the connecting head. The invention is also directed to filter closure systems that are provided for mounting a filter or filter housing of the disposable type as well as those where the filter or filter housing is regularly replaced for maintenance or repair work.
A preferred field of application of such filter closure systems is stationary and movable compressed air devices. The compressors utilized in this field require oil for lubrication, for sealing and for cooling of the moving parts resulting in production of oil-containing gases. In order to recover most of this oil and in order to purify the compressed air by removing the oil, oil-removing elements are required that during maintenance work of the device must be regularly exchanged. These oil-removing elements are the filter elements of an appropriately configured filter arranged in a filter housing. Similar applications exist in connection with vacuum pumps.
Other applications of such filter closure systems are found in liquid filters that remove dirt particles or other components from a liquid, for example, oil filters, fuel filters, hydraulic medium filters, cooling medium filters, water separators or process filters for removing large amounts of contaminants from process liquids, in particular, in case of grinding, eroding or electrical discharge machining processes. Filter closure systems are also used in liquid separators that separate liquid or solid contaminants from a gas stream, in particular, in internal combustion engines, for example when cleaning oil-containing venting gases of the crankcase.
In areas such as oil filtration and removal of oil from air the filter closure system, the system must satisfy in particular the requirements in respect to pressure resistance and temperature resistance. Important features are also a simple, self-evident handling that prevents faulty operation and a cost-efficient production and/or disposal.
Filter closure systems established in the art are primarily based on threaded connections. Here, a filter housing, provided generally with a centrally arranged thread that is located on a terminal disk inserted into the filter housing, is screwed onto a matching threaded socket of the connecting head and by means of a sealing device, for example, an O-ring, a sealing action is achieved. Moreover, bayonet closures are known.
Based on these known devices, it is the object of the invention to provide a filter closure system in which in a simple way a seal-tight connection can be produced that enables a simple, self-evident manipulation that prevents faulty operation and that is cost-efficient with regard to production and/or disposal.